The invention is directed to a reverser for a feederhouse of a harvesting apparatus. The reverser is particularly well adapted for use in combines.
Agricultural combines are typically provided with an outwardly extending feederhouse for directing harvested crop from a harvesting platform into the combine. In difficult crop conditions, it is possible to plug the feederhouse by the harvested grain. As such, some method is needed to free the plug.
U.S. Pat. No. 4,879,868 discloses a reverser assembly that can be used to reverse the feederhouse used for transmitting small grains into the combine. The main driven sheave is provided with an externally toothed cooperating assembly that is selectively engaged by an internally splined drive element that can be moved along the drive shaft. The drive shaft is provided with external splines that cooperate with the internal splines of the drive element so that when the drive element is operably coupled to the toothed cooperating assembly of the main driven sheave, the main driven sheave drives the drive shaft. The drive element is also provided with a gear assembly that can be operably coupled to a toothed cooperating assembly located on the second driven sheave. By sliding the driven element away from the main driven sheave, the drive element disengages the toothed cooperating assembly of the main driven sheave and the second toothed element engages the toothed cooperating assembly of the second driven sheave. Thereby, the main driven sheave becomes operatively disengaged from the drive shaft and the second driven sheave now drives the drive shaft. By coupling the second toothed assembly to the toothed cooperating assembly on the second driven sheave, the output is effectively reversed, reversing the rotation of the feederhouse drive shaft.
The positioning of the drive element is controlled by a push/pull cable having a handle located in the operator""s cab of the combine. The push/pull cable is operatively coupled to a bell crank that is coupled to the drive element by a link.
Another feederhouse drive and reverser assembly is described in U.S. Pat. No. 4,138,837. In this patent, a planetary gear set arrangement is described that facilitates the provision of a reverse drive, including a single ring gear assembly and a control linkage. The ring gear is maintained in his radial position by its engagement of the planetary pinions of the gear set. A shifting collar, splined to an output shaft, transmit output from the planetary gear set to that shaft, selectively engaging either a sun gear for the reduced speed forward drive or, internally, a hub plate attached to the ring gear for the reverse drive. The control linkage includes a push-pull control cable connected to a manual control handle located in the operator""s station.
In the John Deere 10 Series Combine, the reverser is activated by pressing a pedal in the cab that is connected to a push/pull cable routed to the shift collar or drive element in the gearbox. However, when the selected gear and shift collar are misaligned, it is necessary to maintain pressure on the pedal and xe2x80x9cjogxe2x80x9d the front end drive to the on and off position until the gear and shift collar are aligned. Once the components become aligned, the shift collar will slide over allowing the gearbox to be switched to reverse drive.
In the aforementioned assemblies, successful engagement of the reverser depends upon proper drive element or collar and gear alignment. Frequently, the operator must attempt several times to engage the reverser using either the manual lever or pedal, decreasing operator efficiency.
The present invention provides a mechanism for engaging and disengaging the reverse operation of a feederhouse of a harvesting apparatus. The mechanism solves the problem of accurate engagement between the shift collar or drive element and the reverse gear, teeth or splines and the forward gear, teeth or splines of the feederhouse transmission. The mechanism comprises an actuator, electrically controlled, which loads or compresses a spring, wherein the spring exerts a shifting force on a shift shaft or shift fork of the gearbox which moves the shift collar or drive element of the transmission into either a forward or reverse gear engagement.
According to the preferred embodiment, the mechanism includes a plunger. The actuator and plunger are mounted in series with the shift shaft or shift fork of the gearbox, on the bottom side of the feederhouse. The actuator drives the plunger and the plunger compresses the spring. The spring stores the energy provided by the actuator, allowing the shift inside the gearbox to occur when the gears, teeth or splines are correctly aligned. If the gears are meshed correctly, the shift occurs instantaneously. However, if misalignment is present, the spring retains force on the shift shaft or shift fork in the direction of the proposed shift. When the operator selects a shift from forward to reverse, or vice versa, the shift will take place automatically once the gears, teeth or splines are aligned properly.
The required motion to engage and disengage the feederhouse reverser is supplied by the actuator. Preferably, the actuator is an electrically driven device. A switch in the operator""s station or cab allows the user to remotely actuate the actuator to complete the selected motion. Due to the energy stored in the spring, the operator can make a reverser shift selection once, and allow the system to engage when the shift collar is aligned with the selected one of either the forward or reverse gears, teeth or splines.
According to a further development of the shift control of the invention, the engine delivers rotary power to a controllable clutch. The clutch, when engaged, delivers rotary power to the transmission of the feederhouse. A controller is signal-connected to the controllable clutch, via appropriate signal conditioning, to control the engagement/disengagement of the clutch. The operator-controlled switch is signal-connected to the controller.
When the switch is thrown to engage, or alternately to disengage, the reverser, the controller disengages the clutch. A speed sensor monitors the speed of the transmission gears, such as via an output shaft engaged to the driven side of the clutch. When the shaft has stopped, the controller causes the actuation of the actuator. Additionally, the controller can then send a signal to the clutch to pulsate the clutch to cause a slow movement of the gears within the transmission until the reverse gears, teeth or splines, or alternately the forward gears, teeth or splines, are aligned with the shift collar gears, teeth or splines. Once aligned the shift occurs. The transmission can be configured to send a feedback signal to the controller, the signal confirming the successful occurrence of the shift. Alternatively, the controller can cause the clutch to pulsate only for a preset time interval, requiring a second attempt to shift if the shift has not successfully occurred. The controller then engages the clutch and full rotary power is once again communicated to the feederhouse transmission.
According to the present invention, a shift into reverse operation, or back to forward operation, can be accomplished by a simple action of throwing a switch. The operator need not manually jog the gears of the feederhouse transmission in order to mesh the reverse or forward gear assemblies. The shift will be automatically accomplished. The automatic control of the reverser operation will result in less damage due to operator error caused by attempting to shift while the transmission gears have not sufficiently decreased in speed. The switch is easier and more convenient for the operator to actuate compared to foot operated or hand operated push-pull cables. Furthermore the elimination of the push-pull cable eliminates a dust and noise entry point into the cab.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.